This build is for mid-lane domination. It is especially good against Outworld Devourer and heroes without blinks/leaps.
You go boots and link first to let you have huge control over your lane. Walk up to the hero and link them, then follow them to their tower (but don't take tower hits!). This should let you steal enough damage to make taking all the last hits and denies a breeze.
Plasma Field is generally only taken at lvl 5 for the vision, incase someone is trying to juke you through fog of war.